Synthesis And Properties Of Heterogemini Surfactants Containing Rigid Chain

Gemini surfactants are defined as surfactants that are made up of two hydrophobic alkyl chains and two identical hydrophilic groups. Heterogemini surfactants are gemini surfactants with different types of polar head groups, and they not only show a strong propensity to self-assemble at very low concentrations, but also can produce lower surface tensions. This may be due to the attractive interaction between changed head grooups.With these considerations in mind we have designed and synthesized a new type of Heterogemini surfactants that have two alkyl chains and contain two nonidentical head groups. General, the synthesis of Heterogemini surfactant is relatively complex in comparison with that of symmetric ones. The synthesis of such species must be based on different building blocks for the two entities: (a) a coupling agent introduced links two different of amphiphiles; (b) two different of hydrophilic groups are introduced into an appropriate molecule containing two hydrophobic alkyl chainsIn this paper, we adopt method (a). Five heterogemini surfactants were synthesized via Williamson etherfication, NBS brominaction, quaternization and saponification. All final products are characterized by elementary analysis, IR spectra and 1H-NMR spectra and consistent with target products..The preliminary physicochemical evaluations of these surfactants were conducted by surface tension, fluorescence spectrum andπ-A isotherm measurements. Through analyzing their physicochemical properties, so we think we have synthesized Heterogemini surfactants with high surface properties and they exhibits interesting physical properties.